This invention relates to an apparatus for refrigerating articles in which a valve is utilized for selectively introducing the cryogen that is liquid at pressure above the critical pressure but that converts to a solid and then to a gas at this critical pressure with the valve including closure means subjected to the incoming cryogen liquid at a pressure above critical so that the pressure is not reduced until after the cryogen has left the valve.
Another feature of the invention is to provide such a valve for use with this type of cryogen.
Another feature of the invention is to provide a method of refrigerating articles.
The prior art considered in preparing this application consisted of U.S. Pat. Nos. 3,109,296; 3,258,935; 3,813,895 and 3,898,863 of which only the first relates to apparatus and method involving special valving for carbon dioxide refrigeration but the structure disclosed is completely different from that disclosed and claimed herein.